noise reduction, sampler and threshold etc.

[zeronove]

I would like to understand better how the noise reduction process works but
I realized that probably I missed some fundamental infos: which are the differences among "Noise Threshold" in DMC rollout and "Color thresh" in Image Sampler one.

The only thing actually I understand is that unlocking the Color thresh I can fine tune the noise exclusively during the render pass, without affecting the GI pass; so I think about the Color thresh in the DMC sampler as a sort of subset of the Noise thresh, is that right?

Online help doesn't help me so much, anyone has additional theoretical useful infos, links or whatever?

thanx in advance

[victor.nsy]

Hmmm, I think color thresh deals with texture and noise thresh deals with samples.
It's 2 different thing. Have no clue about isolating noise by turning off color thresh,
during render pass.

Care to elaborate the process?

best regards

[dellis]

Go to gnomonology and pick up Chris's lesson..its so cheap and will give you a great understanding of image sampling!

[vlado]

The difference between the two thresholds is that they are used in different places - for example, samples in the irradiance map will be affected by the Noise threshold, but not by the image sampler Color threshold.

Best regards,
Vlado

[zeronove]

thanx guys 4 your replies

@victor.nsy

It seems to me that It doesn't make any difference between textures or solid colors (ex. try to work with a saved GI solution and experiment changing AA type or its values)

@dellis

Chris tutorial was exactly the starting point of my attempts to understand better the noise reduction process.
Actually I'm just trying to migrate what Chris (or Vlado in his Universal settings) suggested into my workflow that rarely includes Brute Force as primary GI method because of its longer render times

@vlado

so it seems that my undestanding was quite correct, probably not exact or scientific, but more or less ...

one more question to you Vlado is the following:

is there any relation among the default value (0,01) for the noise threshold and the IM preset values?

I found that 0,01 could be "adequate" for IM high preset (detailed GI requires fine noise reduction); so my understanding is that for a less detailed GI (IM medium, low or whatever) an higher noise value could be also "adequate" thus leading to faster render time?

thanx in advance

[vlado]

Yes, you are correct; a more blurry irradiance map solution can do with a higher noise threshold - since the noise will be blurred anyways.

Best regards,
Vlado